Process and apparatus for controlling the furrow-depth of a plough drawn by a traction-engine



J. LIPINSKI 3,490,538 PROCESS AND APPARATUS FOR CONTROLLING THE FURROW-DEPTH Jan. 20, 1970 OF A PLOUGH DRAWN BY A TRACTION-ENGINE 4 Sheets-Sheet 1 Filed June l5, 1967 BY v A 1" ma, 4,

.//f ATTORNEY.

Jan. 20, 1970 J. L iPlNsKl 3,496,538

PROCESS AND APPARATUS FOR CONTROLLING THE FURROW-DEPTH OF A PLOUGH DRAWN BY A TRACTION-ENGINE Filed June l5, 1967 4 Sheets-Sheet 2 INVENTOR /7/5 ATTORNEY,

Jan. 20, 1970 J. L lPlNsKl 3,490,538

PROCESS AND APPARATUS FOR CONTROLLING THE FURROW-DEPTH OF A PLOUGH DRAWN BY A TRACTION-ENGINE Filed June l5, 1967 4 Sheets-Sheet S INVENTOR: Jann /f ATTORNEY.

Jan. 20, 1970 J. LIPINsKl 3,490,538

PROCESS AND APPARATUS FOR CONTROLLING THE FURROw-DEPTH OF A PLOUGH DRAWN BY A TRACTION-ENGINE Filed June 15, 1967 4 Sheets-Sheet 4 /f/S- ATTORNEYl United States Patent O 3,490,538 PROCESS AND APPARATUS FOR CONTROLLING 'ITE FURRUW-DEP'IH 0F A PLOUGH DRAWN BY A 'IRACTION-ENGINE Johann Lipinski, Vienna, Austria, assigner to Alex. Friedmann Kathmandu-Gesellschaft, Vienna, Austria Filed June 15, 1967, Ser. No. 646,222 Claims priority, application Austria, .lune 24, 1966, A 6,056/66 Int. Cl. A0111 63/112; F02b 15/00; F15b 15/18 U.S. Cl. 172-1 7 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for regulating the depth of a furrow made by a plough drawn Iby a tractor that has an internal combustion engine with fuel injection including an injection pump and a fuel supply pump. The supply pump is in such a dependence from the engine that any change in the load and thereby in the speed of the engine will result in a similar change of the amount of fuel supplied by the supply` pump; the change of the amount delivered by the supply pump is sensed and is transmitted to hydraulic control means which adjust the depth position of the plough.

When deeply ploughing a eld, the furrow-depth of the plough should be considerable, however, the furrow-depth attainable is limited by the power of the traction-engine. The ground is of different hardness at different places and therefore in absence of a means for controllng the furrowdepth in dependence on the conditions encountered with the ground to be ploughed, it is only possible to work with a relatively small furrow-depth of the plough, so that the power of the traction-engine is not fully made use of. According to a prior art proposal the furrow-depth of the plough is controlled in dependence on the traction resistance on the plough. Adjustment of the plough is effected :by hydraulic means, and with the aid of such hydraulic means the plough can be easily lifted and lowered. For effecting lifting and lowering of the plough in dependence on the resistance for the plough, built up by the ground, it has been proposed to control adjustment movement of the plough in dependence on the traction force existing between traction-engine and plough. With these arrangements a spring is interpositioned into the traction rod like a dynamometre, the variations in length of the spring being used for controlling the adjustment movement of the plough. In case that the total traction-force or a substantial portion thereof is supplied via the dynomometre, there results extremely strong forces, which have as a consequence a heavy and complicated construction and are disadvantageous insofar as such strong traction-forces adversely affect the sensitivity of the control. In case that only a small part of a traction-force is supplied via the dynamometre there results a control of distorted characteristics, and with small furrow-depth of the plough the control may completely fail.

-It is also known to control the furrow-depth of a plough drawn by a traction engine provided with a fuel injection combustion engine in dependence on the amount of fuel injected by the fuel injection pump.

The present invention now aims at improving a process for controlling the furrow-depth of a plough drawn by a traction-engine provided with a fuel injection combustion engine, whereby control of the adjustment movement of the plough is effected by means of a hydraulic control means. Reference is had to my co-pending application Ser. No. 428,015, filed lan 19, 1965, now Patent No. 3,358,774 issued Dec. 19, 1969. The invention essentially consists in that the control of the adjustment movement of the plough is effected in dependence on the amount of 3,490,538 Patented Jan. 20, 1970 fuel supplied, within a unit of time, by a fuel supply pump for the fuel injection pump, said fuel supply pump delivering fuel in dependence on the revolution speed. Such a fuel supply pump is, at any rate, necessary for a fuel injection combustion engine and by selecting such a fuel supply pump supplying fuel in dependence on the revolution speed no additional expenditure results. It has been found that such a fuel supply pump delivering fuel in dependence on the revolution speed, -which supply pump usually supplies a substantially excessive amount of fuel, is in the position to effect pressure variations in a space lying downstream of the fuel supply pump, and that these pressure variations are a suitable basis for influencing the control procedure. When the force acting against the movement of the plough in forward direction increases the speed of the traction-engine, and therewith also the revolution speed of the motor and of the fuel supply pump, is reduced so that it is possible to see the pressure variation, resulting from the now reduced revolution speed of the fuel supply pump, in a space lying downstream of the fuel supply pump to influence, according to the invention, the control such that the plough is lifted for a predetermined distance.

According to a preferred embodiment according to the invention, control may ibe additionally influenced in a manner known per se in dependence on the amount of fuel supplied to the motor by the fuel injection pump. If in view of an increase of the resistance to be overcome by the plough, the speed of the traction-engine, and with this also the revolution speed of the motor, is reduced, there results an increase of the amount of fuel injected in case of fuel injection combustion engines provided with speed control. Such an increase of the amount of fuel injected inevitably results in sucking of a greater amount of fuel from the pressure space of the fuel supply pump so that the pressure within the space lying downstream of the fuel supply pump is varied in the same sense as this pressure is varied when reducing the revolution speed of the fuel supply pump. The pressure difference available for effecting the control procedure thus is increased by making the control means additionally dependent on the amount of fuel injected into the motor. Additionally the sensitivity of the control is increased.

The pressure space of the fuel supply pump can be linited by an overflow valve loaded by a progressive spring means and can be connected to the hydraulic control means. By making the spring means loading the overflow valve a progressive one, there is attained with only small variations in revolution speed and, in consequence thereof in the amount of fuel supplied in a time unit that the pressure in the pressure space of the fuel supply pump is altered to such an extent that through these small variations in revolution speed of scarely 3% the control means of the plough is put into action.

ln accordance with a preferred embodiment of the invention, the overflow space of the fuel injection pump provided with an overflow control is connected to the pressure space of the fuel supply pump. The pressure Within the pressure space of the fuel supply pump is additionally reduced when the amount of fuel injected is increased so that the pressure difference available for control is increased. i

Control of the amount of fuel supplied by the fuel supply pump in a time unit can be made much more effective if, according to the invention, the pressure conduit leading from the space behind the overflow valve delirniting the pressure space of the fuel supply pump is throttled whereby the hydraulic control means is connected to the space between the overflow valve and the throttle. The fuel supplied by the fuel supply pump in excess of the amount required, as a whole, flows into the space lbetween the overflow valve and the throttle so that with a suitable setting of the throttle deviations of the amount of fuel supplied from a predetermined amount of fuel supplied can be easily determined and effectively used for control purposes.

Also with this embodiment it is possible to connect, according to the invention, the overflow space of fuel injection pumps provided this overflow control to the pressure space of a fuel supply pump or to the space between overflow valve and throttle so that again the pressure difference available for effecting control is increased by Varying the amount of fuel injected.

It is convenient to select a throttle with a predetermined throttle section, which throttle section can be empirically determined and is unalterable in operation. It is also possible, ho-wever, to influence control by means of a throttle adjustable during operation, and with such an adjustable throttle it is possible to manually select a basic setting of the furrow-depth of the plough or to lift the plough-share above ground. It is further possible to substitute a throttle with fixed throttle section by a throttle with adjustable throttle section and thus to combine the effect of a fixedv throttle with the effect of an adjustable throttle. However, by such a measure selection of the desired setting is somehow difficult.

The hydraulic control means, which is subjected by the pressure in the pressure space of the fuel supply pump or by the pressure behind the overflow valve, preferably is an auxiliary control means which controls the flow of an auxiliary control fluid to control the supply of pressure fluid to the lifting piston.

The invention is further illustrated with respect to the drawing showing embodiments of the invention.

In the drawing, FIG. 1 is an elevational view of a tractor and a plough provided with an apparatus according to the invention for controlling the depth of penetration of a plough.

FIGURES 2, 3 and 4 are diagrammatic fragmentary sectional views of different embodiments of an apparatus according to the invention.

As is shown in FIG. 1, the tractor has rear wheels 100 and front wheels 101 and is coupled to a plo-ugh 102, which has a plough share 103. The tractor is driven by a Diesel engine 104. Fuel for the Diesel engine is fed by a fuel supply pump 2 from a fuel tank 105 through a conduit 107 to an injection pump 3. The injection pump 3, which corresponds to the injection pump 108 of my aforementioned co-pending application, now Patent No. 3,358,774, discharges the fuel through injection conduits 109 to each of the injection nozzles 4, through which the fuel is injected into the cylinders 110 of the engine. The pressure space S (see FIGS. 2 to 4) of the fuel supply pump 2, that is connected to the conduit 107, is also connected to a return flow conduit 127, and an overflow valve 6 is fitted into said return fiow conduit 127 which enters into the fuel tank 10S, or is connected to the conduit 1. By means of the overflow valve 6, a certain pressure is maintained in said pressure space 5.

Said pressure space 5 of the fuel supply pump 2 furthermore is connected, by means of a conduit 217 with an auxiliary control means 8 and 23, respectively, by means of which the amount of fluid of an auxiliary control medium discharged through a conduit 113 and fed through a conduit 111, is controlled. Conduits 11.1 and 113 lead to a control means or apparatus 112 which controls a hydraulic cycle (system) that actuates the lifting and the lowering of the plough 102.

The hydraulic system liquid is fed by a pump 115 from a tank 114 through a conduit 116 to the control apparatus 112. A return conduit 117 for the hydraulic system liquid leads from the control apparatus 112 back to the tank 114. Another conduit leads from the apparatus 112 to the working chamber 118 of a working cylinder 119. The working cylinder 119 contains a piston 121, which is provided with a piston rod 122. That end of the piston rod 122 which is remote from the piston, is pivoted to the .4 lifting linkage 123 of the vplough 102. An upward movement o-f the piston 121 will thus effect a lifting movement of the ploughshare 103, Whereas a downward movement of the piston 121 will lower the ploughshare 103 deeper into the ground.

In the control apparatus 112, the conduit 116 is connected to the return conduit 117 and the conduit 120 is shut off, or the conduit 116 is connected to the conduit 120 or the conduits 116 and 120 are connected to the return conduit 117. When the control apparatus 112 connects the conduit 116 to the return conduit 117 and the conduit. 120, and the working chamber 118 of the working cylinder 119 is shut off, the plough 102 remains in its position. When the conduit 116 is connecte-d to the conduit 120, however, there will be a pressure rise in the working chamber 118 of the working cylinder 119, so that the piston 121 ascends and the plough 102 will be lifted. When the conduit 120 is connected to the return conduit 117, the working chamber 118 of the working cylinder 119 will be pressure-relieved and the piston 121 will descend so that the plough 102 will be lowered under the action of gravity into the soil to be cultivated. A lever 124 enables an adjustment of the depth of penetration of the plough in a lifted condition, for instance, for road travel.

With all embodiments shown in FIGS. 2, 3 and 4, fuel is supplied by means of a fuel supply pump 2, from a fuel tank through a conduit 1 to the fuel injection pump or fuel injection pumps 3. The fuel injection pump 3 distributes fuel to the injection nozzles 4. In Some cases it is convenient to provide an auxiliary pump in addition to the fuel supply pump 2 and to arrange such an auxiliary pump within the conduit 1 between the fuel tank 105 and the fuel supply pump.

With all embodiments shown the fuel supply pump 2 is a vane pump which has a speed-dependent pressure characteristic. The pressure space 5 of the fuel supply pump which is formed by the conduit leading to the fuel injection pump 3 or the fuel injection pumps, respectively, is limited by an overflow valve 6 by means of which a predetermined pressure can be maintained Within the pressure space 5.

With the embodiment shown in FIG. 2 the overflow valve 6 is loaded 'by a progressive spring 7. To the pressure space 5, by means of a conduit 21, an auxiliary control means 8 is connected which comprises a diaphragm 9 subjected to the pressure existing in the space 5. The diaphragm 9 is connected with a valve plate 11 by means of a pin 10 and the valve plate 11 is loaded by a spring 12 in direction of the closed position. Prestress of the spring 12 can be adjusted by turning the abutting part 13 having the form of a screw. The valve plate 11 controls the amount of flow of an auxiliary control fluid which is supplied and discharged via the conduits 111 and 113, respectively.

By means of the mentioned auxiliary control uid, a control apparatus 112 is subjected to pressure, and the control apparatus 112 controls the supply of pressure fluid to the working chamber 118 of a lifting piston 121 serving for lifting the plough 102.

With the embodiment shown in FIG. 2 the fuel injection pump 3 is an injection pump provided with overflow control and discharging any excessive amount of fuel into its suction chamber (one-flow fuel injection pump). The working space 16 of the injection piston 17 of such a fuel injection pump is completely filled with fuel during the suction stroke, and adjustment of the fuel to be injected is effected by opening the suction part 18 by means of an oblique groove of the piston 17 during the injection stroke, whereby fuel pressure is released from the working space 16. With the one-ow fuel injection pump shown in FIG. 2 more or less fuel flows back into the conduit 5 in dependence on the amount of the fuel actually injected so that the amount of fuel flowing back is a measure for the amo-unt of fuel injected.

If now, in response to a harder ground or to up-hill movement or to increased friction of the plough in the ground, the speed of the traction-engine, and with this the revolution speed of the motor and of the fuel supply pump driven by said motor, is reduced, also the pressure in the pressure space 5 of said fuel supply pump is reduced, whereby in view of the spring 7 loading the overow valve 6 being a progressive one, a pressure drop sucient for effecting plough control is produced with only small changes in speed of revolution. By such a pressure drop the valve plate 11 is moved in direction of the closed position by means f the spring 12 so that the pressure uid supplied from the conduit 111 and discharged via the conduit 113 to the control apparatus 112 is throttled. This results in shifting the control piston 121 in a sense effecting lifting movement of the plough. The pressure drop within the pressure space of the fuel supply pump is further increased in view of the fact that with decreasing speed of the traction-engine, and with this also of the revolution speed of the motor, the position of the controller of the fuel injection pump is changed in the sense for increasing the amount of fuel injected so that less fuel is flowing back into the pressure space 5 of the fuel supply pump.

If ground conditions allow for a greater furrow-depth of the plough, then the speed of the traction-engine and with this also the revolution speed of the motor and of the fuel supply pump, will increase so that within the pressure space 5 of the fuel supply pump 2 supplying fuel in dependence on the speed of revolution the pressure will also increase and the now increased pressure will act on the diaphragm 9 in a sense to further lift the valve plate 11 from its seat. With this the amount of auxiliary control fluid fed from the conduit 111 and discharged via the conduit 113 to the control apparatus 112 is increased which results in positioning the control apparatus 112 and thereby the piston 121 in a sense to lower the plough 102. Further, with increasing revolving speed of the motor the controller of the fuel injection pump will adjust this pump in a sense to reduce the amount of fuel injected so that the amount of fuel fed back into the conduit 5 is increased. As a result of this measure a pressure increase within the pressure space 5 is to be observed which additionally contributes to the pressure increase effected within this pressure space by the higher speed of revolution of the fuel supply pump 2.

Lifting movement and lowering movement respectively, of the plough, lasts until the traction-engine again has reached its original speed and, respectively, the motor has reached its original speed of revolution. In this moment, the pressure within the pressure space 5 again has attained its original value and the valve plate 11 of the auxiliary control means 8 has again reached its original position which corresponds to the neutral position of the control piston.

Also with the embodiment shown in FIG. 3 the pressure'space 5 of the fuel supply pump 2 is delimited by an overow valve 6, whereby, however, the spring 7 loading this overflow valve 6 need not necessarily show a progressive characteristic. By this overflow valve 6 the excessive amount of fuel fed by the fuel supply pump 2 is, in a manner known per se, fed back into the suction space of the fuel supply pump 2. Into the feed-back or bypass conduit 19 located downstream of the overflow valve 6 a throttle 20 is positioned, and at a position between the throttle 20 and the overflow valve -6 a conduit 21 leading to the working space 22 of an auxiliary control means 23 is branched olf from the feed-back conduit 19. Within the working space 22 of the auxiliary control means 23 a diaphragm 24 is arranged which is connected via a pin 25 with a valve plate 26 and loaded by a spring 27 in direction of the closed position of the valve plate 26. The valve plate 26 again controls the amount of flow of an auxiliary control lluid which is supplied and discharged via the conduits 111 and 113, respectively. The discharge conduit 113 is connected with the working space of the control apparatus 112, which controls the supply of pressure fluid to the working chamber 118 of the lifting piston 121 for the plough.

Operation of the apparatus shown in FIG. 3 is similar to that of the apparatus shown in FIG. 2. In case that on account of the ground to be ploughed being harder or on account of up-hill movement or on account of increased friction of the plough in the ground, the speed of revolution of the motor and with this of the fuel supply pump is decreasing, also the pressure between the overflow valve 6 and the throttle 20, and with this also within the working space 22 of the auxiliary control means 23, is decreased, which results in a shifting of the valve element 26 under the action of the spring 27 in direction of the closed position so that the auxiliary control -uid will be fed via the conduit 113 to the control apparatus 112 in a smaller amount. Thereby the control piston 121 is shifted in a sense to effect lifting movement of the plough. If, on the other hand, the ground conditions allow for a greater furrow-depth of the plough, then the revolution speed of the motor and of the fuel supply pump will increase and with this also the pressure within the working space 22 of the auxiliary control means 23 is increased. Thereby, the valve element 26 of the auxiliary control means 23 is shifted in the direction to open the valve so that the volume of the auxiliary control uid at the control piston is increased and this control piston is shifted in a sense to lower the plough. Also with this embodiment pressure variations between the overow valve 6 and the throttle 20, and with this within the working space 22 of the auxiliary control means 23, are amplified, as with the embodiment shown in FIG. 2, by those pressure variations which are effected within the pressure space 5 on account of varying the amount of fuel fed back by the fuel injection pump 3 during its injection stroke. Also in the case of the embodiment according to FIG. 3 lifting movement and lowering movement, respectively, of the plough last untll the traction-engine has reached its original speed and the motor has reached its original speed of revolutron, respectively.

The throttle 20 conveniently is provided with a sectron not alterable during operation, and the throttle section can be determined empirically. To provide for the posslbllity to select a predetermined furrow-depth for any possible range of motor speed an adjustable throttle 30 is additionally provided and arranged to shunt the throttle 20 and thereby to feed back an additional amount of the overflowing fuel into the suction space of the fuel supply pump 2. It is also possible to do without an additional adjustable throttle 30 and to make the throttle 20 itself adjustable, whereby, however, it has to be considered that the throttle 20 in each setting position must provide for a `certain free flow section for fuel fed back to the inlet of the pump 2.

The embodiment shown in FIG. 4 differs from that shown in FIG. 3 only insofar as a so-called two-flow fuel injection pump 3' is used with which fuel not injected into the combustion engine during the injection stroke of the pump is fed back into a separate collection chamber 31 instead of into the suction space of the fuel injection pump. The injection pump 3 corresponds to the injection pump 108 of my aforesaid copending application, now Patent No. 3,358,774. The collection space 31 is, according to the embodiment shown in FIG. 4, connected to the feed-back conduit 19 by means of a conduit 32 which is connected to the feed-back conduit 19 at a position between the overflow valve 6 and the throttle 20. If now, for instance on account of the ground to be ploughed becoming harder, the revolution speed of the combustion engine decreases, then not only a smaller amount of fuel is supplied by the fuel supply pump 2 into its pressure space S but also a smaller amount of fuel is fed back by the fuel injection pumps 3 via the collection chamber 31 into the feed-back conduit 19 at a position between the overflow valve 6 and the throttle 20 on account of the controller of the fuel injection pump having provided for a greater amount of fuel to be fed to the injection nozzles 4. In consequence thereof the pressure between the overflow valve 6 and the throttle 20 decreases so that the valve element 26 is moved under the action of a spring 27 in direction of the closed position. As already mentioned, such adjustment movement of the valve element 26 results in positioning the control piston in a sense to lift the Plough. On the other hand, with the ground to be ploughed becoming softer, the revolutio-n speed of the combustion engine is increasing so that the fuel supply pump 2 supplies more fuel and further by the controller of the fuel injection pump 3' a greater amount of the fuel supplied to the fuel injection pump is fed back into the collection chamber 31. In view of these two 'facts a pressure increase between the overflow valve 6 and the throttle 20, and with this also within the working space 22 of the auxiliary control means 23, is effected which acts in a sense to shift the control apparatus in the direction necessary for lowering the plough.

What I claim is:

1. In a method for regulating the depth of the furrow made by a movable plough drawn by a tractor having an internal combustion engine with fuel injection including an injection pump fed by a fuel supply pump, and hydraulic control means operable for adjusting the depth position of the plough,

the steps comprising,

placing the supply pump in such a dependence of the engine that any change in the load and thereby in the revolving speed of the engine will result in a change, in the same sense as the change of the engine speed, of the rate of fuel delivered to the injection pump, sensing the change of the rate delivered by said supply pump due to engine speed change, and transmitting the sensed change to said hydraulic control means.

2. In a method, as claimed in claim 1, said sensing also sensing the rate of fuel injected into the engine by said injection pump. j j

3. An apparatus, for regulating the depth of the furrow made by a movable plough drawn by a tractor having an internal combustion engine with fuel injection including an injection pump and a fuel supply pump, and hydraulic control means operable for adjusting the depth position of the plough,

comprising, said supply pump being a positive displacement pump driven by saidengine and having a pressure space, a spring biased overflow valve limiting the pressure existing in said pressure space, conduit means connecting said pressure space with said hydraulic control means,

said injection pump also being responsive to the engine lspeed and having an overflow space and an overow control means and having an inlet intercom- Imunicating `with said overflow space and being connected to said pressure space of said supply pump, whereby the output of said supply pump supplies said inlet of the injection pump with fuel.

4. An apparatus for regulating the depth of the furrow made by a movable plough drawn by a tractor having an internal combsution engine with fuel injection including an injection pump and a fuel supply pump, and hydraulic control means operable for adjusting the depth position of the plough,

comprising, said supply pump being a positive displacement pump driven by said engine and having a pressure space, a spring biased overflow valve limiting said pressure space,

said injection pump also being responsive to the engine speed and having an overflow space and an overflow control `means and having an inlet intercommunicating with said overflow space and being connected to said pressure space of said supply pump, whereby the output of said supply pump supplies said inlet of the injection pump with fuel, a bypass space disposed in parallel with said overflow valve, a throttle operable for throttling the discharge of fuel from said bypass space, said hydraulic control means being connected to a section of said bypass space between said overflow valve and said throttle.

5. Apparatus a's claimed in claim 4, characterized in that for throttling the fuel discharge from the bypass lspace an invariable throttle section is provided.

6. Apparatus as claimed in claim 5, characterized in that in addition to the invariable throttle section an adjustable throttle for controlling the fuel discharge from the bypass space is provided or in that the`invariable throttle section is substituted by a variable throttling means.

7. Apparatus as claimed in claim 3, characterized in that the hydraulic control means is an auxiliary control means for controlling the ow of an auxiliary control fluid to a control piston which controls the ow of pressurized fluid to a lifting piston.

References Cited UNITED STATES PATENTS l, 377,602 5 1921 Rutherfurd 172--3 2,629,306 2/ 1953 Rusconi 172--2 3,256,940 6/ 1966 Asheld 172-9 3,358,774 12/1967 Lipinski 172-3 FOREIGN PATENTS 1,432,612 2/ 1966 France.

EDGAR W. GEOGHEGAN, Primary Examiner Us. c1. Xn -19, 52; 172-8 

